1. Field of the Invention
This invention a relates to musical instruments having a hollow body including an opening or hole for sound to escape from the hollow body and a fret board provided with strings that extend across the sound hole, and particularly to a detachable and adjustable sound feedback control device mounted on the instrument in cooperative association with the sound hole and adjustable to control the decibel level of the musical sound notes that emanate from the sound hole.
2. Description of the Prior Art
Prior art pertinent to this invention includes U.S. Pat. Nos. 3,636,809; 4,024,788; 4,394,830 and 4,632,003.
U.S. Pat. No. 3,636,809 discloses dual opposingly positioned sound holes incorporating a sound hole cover device capable of generating a variety of tonal colors ranging from a selection of total occlusion to zero occlusion or full opening thereof.
U.S. Pat. No. 4,024,788 discloses a sound hole cover muting device for a guitar whereby the muting of the guitar is accomplished with a fully occlusive sound hole cover provided with a downward projecting resilient member that extends through the sound hole.
U.S. Pat. No. 4,394,830 discloses a sound hole cover feedback reducer for acoustic and electric guitars, and in particular, as shown in FIG. 5 of that patent, the sound hole cover member is integrally provided with a plurality of resilient finger members shaped with so-called xe2x80x9cinclined detent cam surfacesxe2x80x9d operable for effecting cover retention by deforming radially inward during sound hole insertable installation and returning to the un-deformed retention attitude once insertable cover affixation has been accomplished and thereby collectively functioning to hold the cover in place.
U.S. Pat. No. 4,632,003 discloses a variety of devices adapted to be mounted in the sound hole of a stringed instrument and having on its peripheral underside a cushioning gasket and a plurality of integral circumferentially spaced downwardly and radially outwardly projecting fingers adapted to slip under the associated peripheral edge portion of the sound hole to retain the device in operable association with the sound hole.
The instant invention, however, provides new and useful structural and functional features in the art of stringed musical instrument sound quality enhancement and control devices by a combination of elements not taught by the prior art, resulting in the present device embodying construction features of novel merit as set forth hereinafter.
One of the principal objects of the present invention is the provision of a detachable and adjustable cover member for the sound hole of a stringed musical instrument having a hollow body and a generally circular hole or aperture through which sound normally emanates when the instrument is played and the hole is open or non-occluded.
Another object of the invention is the provision of a detachable and adjustable sound hole cover device that may be selectively applied to sound holes of different diameters ranging from 3xc2xcxe2x80x3 to 4xe2x80x3.
Still another object of the invention is the provision of a detachable and adjustable sound hole cover device that may be applied to help elimination of feedback in electric acoustic instruments, such as guitars, and to adjustably control sound emanating from the sound hole in conventional non-acoustic stringed instruments.
Another object of the invention is the provision of a sound and feedback control device that includes a generally circular base plate detachably mounted in overlapping association with the a peripheral portion of the sound hole or aperture in the musical instrument and having formed therein independent openings that communicate with the interior of the hollow body, with a second element constituting a rotatable plate having occlusive areas corresponding with the independent openings in the base plate and pivotally mounted on the base plate and for digital manipulation to selectively either cover or uncover the independent openings formed in the base plate.
A still further object of the invention is the provision of an occlusivally adjustable and detachably mountable cover member for the sound hole of a stringed instrument that is easy to install and remove, which fits snugly and sealingly over the sound hole and which includes an adjustable apertured dial enabling selection of the desired opening or closing of the sound hole.
Yet another object of the invention is the provision of an occlusivaly adjustable and detachably mounted cover member for the sound hole of a stringed instrument wherein the surface of the base member facing into the sound hole is provided with a layer of acoustic absorbing material and the confronting surface of the adjustable apertured dial pivotally mounted on the base member is also provided with a layer of acoustic absorbent material.
A still further object of the invention is the provision of an occlusivaly adjustable and detachably mountable cover member for the sound hole of a stringed instrument, such as a guitar, wherein the cover member is provided with a latterly extending plate portion on the surface of which are provided pockets for removably retaining guitar picks or other devices.
Yet another object of the invention is a sound hole cover device as illustrated and described to which may be detachably secured a humidifier assembly for controlling the humidity within the hollow musical instrument.
The invention possesses other objects and features of advantage, some of which, with the foregoing, will be apparent from the following description and the drawings. It is to be understood however that the invention is not limited to the embodiments illustrated and described since it may be embodied in various forms within the scope of the appended claims.
In terms of broad inclusion the invention comprises a detachably mountable and occlusivally adjustable cover member for the sound hole of a string instrument, such as a guitar, to enable complete closure of the hole or digitally adjustable to provide varying degrees of opening of the sound hole. The cover member incorporates a flat base plate having a top surface and a bottom surface configured circularly about a central axis. The flat base plate is circularly configured about the central axis to overlap a circular peripheral edge portion of the sound hole and may also be provided with chordal projections adapted to embrace the associated end of a fingerboard. Alternatively, an arcuate portion of the base plate may be cut away to provide a chordal edge adapted to abut the associated end of a fingerboard, sometimes referred to as xe2x80x9cfretboardxe2x80x9d. The base plate is provided with two generally triangular openings the apices of which are coincident along a common plane that is diametrically offset from the central axis and lie on opposite sides of a pivotal axis that is coincident with the common plane that is diametrically offset from the central axis. Pivotally mounted on the base plate on the pivotal axis that is offset from the central axis is a circular adjustment plate or dial of less diameter than the base plate and circularly symmetrical about the pivotal axis. Formed in the circular adjustment or dial plate diametrically on opposite sides of the pivotal axis are a pair of generally triangular openings of substantially the same size and configuration of the generally triangular openings in the base plate. Means are provided on the outer peripheral edge of the rotatable adjustment plate to digitally effect selective rotation of the adjustment plate in relation to the base plate. When the generally triangular openings in the adjustment plate are circumferentially displaced so as to coincide with the openings in the base plate, the coincident openings uncover a specific area of the sound hole. From this position of the rotatable adjustment plate, the adjustment plate may be rotated clockwise or counterclockwise to progressively diminish the open area of the sound hole until it is totally occluded. Means are provided on the underside of the base plate and the adjustment dial plate to acoustically absorb sound emanating from the sound hole and to provide a seal between the base plate and the instrument body and between the adjustment plate and the associated surface of the base plate. In another aspect of the invention a humidity control device may be mounted on the underside of the cover plate assembly for protrusion within the hollow instrument body to maintain a desirable humidity within the instrument body despite the outside atmospheric humidity.